ncurses: bump to 6.0

ncurses: bump to 6.0

ncurses 6.0 has been out for a while now (August 8th 2015!), so this
patch brings us up to the latest version.

- The first patch is no longer needed as it was fixed in the new
  release.
- The other two packages are still applicable, so they have been
  updated to apply properly on the new ncurses version.
- A new option: --with-pkg-config-libdir has been added. Without it
  pkg files wouldn't install to the correct location.
- NCURSES_ABI_VERSION is no longer needed, as there is only 6.

Signed-off-by: Adam Duskett <Adamduskett@outlook.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>